SPINNER II

How To Build SPINNER II at Home

After having the BlueCor material on hand for almost a year, it was finally time to do something with it. Thanks to Mr. Chaitu for demonstrating just how well flat pate airfoil airplanes can fly; & thanks to Mr. Sai Kumar for the neat CD-ROM type motor.

I needed something on which to fly this impressive motor, and
after seeing several planes flying so impressively earlier this
year, and then seeing several hobby clubs in India doing plane flying events, at Bangalore & Delhi, then talking a
bit more with Chaitu, I decided that it was time to finally get busy!

(Winter is building season for me- it's when I take a bit of time
now & then to work on a project. So I thought I'd pass along a few
details on how easy it can be to build one of these airplanes. If it
gets some of you interested in building your own, then my time writing
up these brief notes will be rewarded!

(There are no 'plans' as such- it doesn't really take any- but I
did lay out cutting template patterns on poster board so that more parts
can easily be marked. Blog Following Members can contact me if they are
interested in building one of these airplanes after the flight testing
is actually completed.The building process is very straight forward, and
will be well illustrated in these photos & text. Well to say this is the easiest way in building a minimum level plane at home itself without any hard tools , importing parts, assembling, crashing & again importing.)

I say that a 12 Ounce plane would have great performance
with the 16 Ounce thrust motor,(& I certainly agree!), so that was
the target weight limit if possible. BlueCor fan fold panels are 23-1/2"
between folds, and 50" wide, so length of the fuselage horizontal panel
was dictated at the 23-1/2" length by the material. This is what
should be considered as 'close-coupled'; a longer tail moment would
result in a smoother flying aircraft... but hey, I'm the guy that enjoys
flying the "Short Hare"... this layout is not as close-coupled as that
plane, and I have a lot of fun flying it...!
After doing a rough layout on graph paper, I started my final layout
directly on the foam sheet. I cut the bevels on the aileron / wing joint
in the main cutting session, and merely swapped the ailerons to the
opposite sides to use them as they came out.

The result of my efforts it a total of about one day are in the photos I've attached.

The entire wing, horizontal fuselage member, and horizontal
stabilizer are kept together, cut in one continuous piece. The Vertical
fuselage is longer by another 2-1/8", surrounding the motor. Fuselage
finished length is 30" from the front of the prop mount to the trailing
edge of the elevator.

Wingspan was designed at 30", with a single 1/8" diameter CF
tube wing spar (which was installed in a slot made with a Dremel cutter
bit in a Dremel Tool equiped with a router head setup. I installed it in
the 1/8" deep slot with 5 minute epoxy.

The motor mount ( a 5/16" diameter dowel to insert into
motor mount) was epoxied in place next. (I actually replaced the one in
these first photos with a longer one that extends back farther through
the core of the fuselage past the battery pack mounting area, to firmly
transfer the motor thrust and the battery weight to the rest of the
airframe.)

The top fuselage piece was then epoxied in place, (using one
toothpick piece as a locating pin close to the tail to help alignment
while the epoxy set up.)

The elevator was then tape-hinged to the horizontal stabilizer (after
having the center section reinforced with some 1/2" wide .007" C.F.
material.) I use Scotch multipurpose transparent tape for hinging
purposes, applying the top side tape first, then another layer from the
underside second, so that the tape pieces join to each other in the
middle of the hinge line.

The lower fuselage was epoxied in place next, again using a short toothpick piece as a locator pin at the tail end.

The rudder was next reinforced with CF material in the control horn area, then tape-hinged to the vertical stabilizer.

Finally, the Ailerons were tape-hinged to the wing.

I plan to glue the 1/32" birch plywood control horms into place in
custom slots through the BlueCor foam. Ordorless CyA was used &
worked well for this job. (Since I'm intolerant of solvents, but like
quick setting time, the epoxy and the odorless CyA glue are my choice
for building. I'm also using a bit of low temperature hot melt glue in
certain areas; it's likely only suitable for places where you can work
fast before the glue cools too much to bond well. I'll use 1/32" music
wire for aileron control linkage ends, attached to the ends of .060"
solid CF rods for all control rods.

Result?: Airframe is at about 3-7/8 Oz, before painting.

So this is the progress I made in less than one day, starting from scratch & laying it out before starting the cutting.

[Once the painting was completed it was 1/2 ounce heavier, ready for the control system installation.)

PAINTING

I tested some bright spray paints, and confirmed what others say;
only certain products can be used on the BlueCor without damaging the
material. I had a 3 Oz. can of PACTRA spray paint designed for painting
polycarbonate bodies on RC cars; it did not attack the BlueCor's plastic
surface film, but did bond well to it. (It does attack the core foam,
however, so use it carefully & don't try to pain too 'wet' ; use
mist coats with the spray can held at a distance, and let dry between
coats.) I used this on the entire lower surface of the aircraft.

I used the inexpensive CERAMICOTE acrylic paints from WalMart's
craft section in Purple and black to dress it up a bit on the upper
portion; these colors were applied with a brush. The result isn't too
hard to look at...! It's definitely highly visible from below when it's
in the air!

I used three of the inexpensive Blue Bird .21 Oz servos, installed with low temperature hot melt glue.

I custom made 1/32" birch ply control horns, and glued them in place with odorless CyA glue.

I installed a .3 Oz. GWS 6 channel receiver, then mounted the
1-1/2 Oz motor, 1/4 Oz. Phoenix 10 ESC, & a prop. With a 3 cell
Li-Ion 1200 mAH battery which weighs 4-1/8 Oz, the completed aircraft is
ready to fly at 12-1/8 ounces. I used an APC 9x4.7 slowflyer prop for
the first flights, then later switched to an 8x6 GWS slowflyer
propeller; this motor performs well on this prop on 1 3 cell Lithium
battery.

Flight tests were finally flown on Sunday, December 26th, 2004 in
a small area just off the end of my driveway; this plane is flying
great, and does not need a lot of area to fly. It is close-coupled
enough to flat spin nicely; because of this ccharacteristic, it's
definitely not a trainer! But it flies inverted nicely, rolls smoothly
& loops tightly, and glides under reasonable control with the motor
off, for predictable landings in a modest amount of space. (A flat plate
wing is certainly not intended as any form of 'glider', but power off
landings are essential on a no-landing-gear aircraft, so I'm very
satisfied with the no-power maneuvering capabilities.

Note: 1-18-05: I'm now using a KOKAM 1500mAH LiPo battery to fly
this aircraft; it's producing more RPM than than it did when using the
surplus Li-Ion cells on which I first flew it.)

They say 'A picture is worth a thousand words", and since I type
slowly & do not have time to write up a lot of the details right
now, I'll simply offer the following photos.

QUICK NOTES:

Balance on a flat plate winged aircraft works well at about 29%
to 30% of the wing chord. I had installed the C.F. tube spar at 30% of
chord, and flying with the balance on the spar at the 30% location works
well.

Receiver Antenna: this is taped on top of the wing, rather than draging out behind.

Battery Update 1-18-05: the location of the battery was the last
item I dealt with, to finalize the balance. It is now held in place in
it's cutout with a couple of clear plastic covers (made from salvaged
packaging materials) which are taped in place on either side. One side
is tape hinged, so that it can be swung open for battery placement /
changing, and taped shut for flight.

LINKAGES: Note the 'safety pin' front ends on the control linkage
rods; these are formed from 1/32" music wire, and installed on the ends
of the C.F. rods with heat shrrink tubing. Once final trim alignment is
adjusted with the radio trims centered, a drop of CyA glue locks these
links to the rods. (The other end uses a short Z bend coupler, anso
heat-shrink & glue mounted to the control rod.)

Parting notes: For a novice pilot, making a longer fuselage would
smooth out the handling, but you would have to use a different layout,
with a separate wing, and separate fuselage members, to extend the
length. (Keep in mind the dimensions of the fan-fold sheet.)
In the process, you would likely loose the flat-spin capability, and
find a bit smoother handling.)

Updates: The "SPINNER"; second fuselage being
built for a 10mm square stick mount; specificly, nose layout set up for
the Balsa Products BP21 or BP12 Outrunner motor.

After installing the spar with ordorless (foam safe) CyA glue the
10mm square motor mount stick is glued in place; it extends back to the
wing spar. The top surface of the motor mount stick is placed flush with
the top surface of the wing section of BlueCor- it extends 1/8" below.

Once the vertical fuselage section is split lengthwise and
trimmed out to match & clear the motor installation, the top piece
is glued in place. Toothpick sections are used as 'locator pins' when
gluing the top section in place; (match the trailing edges at the hinge
lines for the elevator and rudder.) Once the 5 minute epoxy I used was
set for a few minutes, I did a final fit on the ailerons and then
tape-hinged them in place. The elevator was tape-hinged in place next.
(Tape top first, then bottom after.)

Above is a closer view of the upper nose section; the motor stick was
installed at an over-long length, then trimmed back to leave the motor
recessed enough to be protected by the lower fuselage section once it is
all together.

After fitting the lower fuselage section to the under-side of the
horizontal wing section, I added 'doublers' on either side of the lower
forward fuselage section, from the nose back to the wing spar area. This
will make this area, which not only carries the flight battery, but
also inevitably takes the most wear & tear on landings, much more
durable. It also brings it out to a full 3/4" thick, so the 3 cell KOKAM
1500 LiPo battery I am using will fit within this thickness, and not
protrude out the sides. I'll determine the battery location last as the
final 'balancing act', and make a snug fitting cutout. For winter
flying, a clear plastic cover will be permanently taped in place on one
side, and another clear plastic battery compartment cover will be
tape-hinged on the other side, and closed with tape to keep the battery
in place.

(Protecting LiPo batteries form damage on landings is a high
priority!) For warm weather flying, the solid cover panels may be
modified to allow for battery cooling air flow; but for winter flying
here in the central Colorado Rockies, keeping the battery warm enough to
perform well is an important consideration.)

You can also see the toothpick 'locator pins' I installed which
will index the lower fuselage section into it's exact desired position
while the epoxy glue is setting.

Once the epoxy had set, I used a bit of low temperature hot melt glue
to lightly reinforce the forward joining area. Then I did an overlay
along the bottom forward edge with 1-1/2" wide cross-fiber nylon
filament tape. 3/4" wide nylon filament tape is used on the aft lower
fuselage bottom edge to add durability.

The photo above shows the BP21 motor installed, mounted on a trimmed
down GWS motor mount (which is included with the BP21 motor.) You do
have to figure out where to drill the lower two holes for mounting the
motor to the mount, but it is a good fit, with the prop shaft center
line just above the upper surface of the motor mount stick. I trimmed
away as much excess plastic as possible; the results are shown in this
photo.)

SPINNER III

This is the latest generation of the SPINNER design series! SPINNER III features a three layer wing leading edge for the front 30% of chord and a sharp 90 degree 'Kline-Fogleman step'. The wing spar structure consists of a 1mm diameter carbon fiber rod glued to the top & bottom surface just in front of the step at 30% of chord. The result is a very rigid wing which flies much more like a fully symmetrical wing than like a flat plate wing - a major performance improvement over the earlier SPINNER design.

A more powerful 2409-18 brushless motor is used on this version of the Spinner. I'm flying a 3S1020 mAH battery pack in this SPINNER; (my older KOKAM 3S 1500 mAH packs are aging, and do not provide anywhere near the power / RPMs.

The counter-balanced tail improves elevator response, with less loads on the servo.

The added tape-on landing gear makes ground handling easy when flying from suitable areas ; takeoffs, landings, and touch-and-goes are possible. When building the fuselage, a epoxied a layer of 1/16" birch ply to the fuselage belly, then covered it with Scotch Cross-filament tape. The landing gear is simply taped in place to this plate with more of the cross-filament tape. A tail skid wire was also installed and taped in place.

This is a very smooth handling aircraft, with unlimited vertical performance!

***Note***This method is done by Mr. Bruce Stenulson's and pictures has been taken himself personally. Click here to visit his personal page for more information.